Fuze self destruction delay and point detonation mechanism



Aug. 9, 1960 A. s. BENNETT Fuza SELF DESTRUCTIONDELAYAND POINT nEToNATIoN MEcHANIsM Filed Dec. 29, 195e 'FUZESEL'F DESTRUCTION DELAY AND POINT DETONATION MECHANISM Arthur S. Bennett, Rochester, NY., assignor, by mesne assignments, tothe United States of America as represented by the Secretary of the Anny Filed Dec. 29, 1958, Ser. No. 783,629

3 Claims. (Cl. 102-86.2)

VThis invention relates to a fuze self-destruction delay and point detonation mechanism and more particularly to a novel means for releasing the firing pin in a fuze mechanism either `upon* target impact or by a self-destruc- Y tion time delay mechanism.

The self-destruction mechanism of the invention is intended for use in a fuze of the type disclosed in Ia co- `pending application tiled May 27, 1955, Serial No. 511,807, now Patent No. 2,889,778, for Fuze Safety Device, wherein the firing pin of the fuze is held in a safe position by a wire connected to the nose cap of the fuze which is released to fire a detonator only upon fracture of the nose cap.

It isa primary object of this invention to provide a mechanism for .the self-destruction of a projectile upon failure to strike 4a target after a predetermined time delay.

AnotherI object is to provide a fuze for use with a projectile acting as a super-quick detonating device or as a self-destruction time delay `mechanism for a projectile.

A further object is to provideV a self-destruction and point detonation mechanism that is reliable and positive in action yet simple Yand economical in design.

The `specific nature of the invention as well as other objects and advantages thereof, will be apparent from the following description of the' preferred embodiment `thereof as illustrated in the accompanying drawing, formingrpartof the speciiication, and in which like numerals are used to designate like parts throughout the same.

IIn the drawings: Y

Fig. l is a longitudinal fragmental sectional view taken through a fuze and illustrating somewhat schematically a pointdetonation and self destruction mechanism of the invention, the elements beingA in unarmed position,

Fig. 2,'is a fragmentary section similar to Fig. l and showing the elements in point detonating position,

Fig. 3 is a fragmentary section similar to Pig. 2, the elements being in the Vself-destruction position, and,

Fig. 4 is lan enlarged fragmentary section illustrating the firing pin and release member in the locked position ofFig.1. l W- Y Referring now to -the drawing, 1 indicates generally the mechanism of the invention housed in a fuze body 2 which is attached to a projectile (not shown). Fuze body` 2 provided with a nose capV 3 and is coaxially bored as at 4, 5,6 and 7 tohouse the operating mechanism of the invention. Bore 7 houses a detonating charge 8 and a booster charge 9. Bore 6 receives a housing 10 which is bored as at 11 `to receive a tiring pin assembly designated generally by 12. The firing pin is slidably mounted in a bore 13 in the assembly and comprises a head 14, a ling point 15 and a stem 16. A coil spring 17 mounted in bore 13, normally biasing against head 14, urges pin 12 towards detonator 8. Stem 16 extends forwardly into a chamber, indicated generally by 18, formed in the forward portion of housing 10 and is provided with a notch 19 in its forward portion. The forward wall of notch 19 is beveled as best viewed in Fig. 4.

Releasable means to hold ring pin 12 in retracted safe position is provided and comprises a release member indicated generally by 20 and notched in its rearward por-A tion as at 21 is connected at its forward end to a wire 22 which is attached as at 23 to a threaded member 22a which is threadably engaged to nose cap 3. Notch 21 is similar to notch 19 and denes a beveled rearward Wall. (See Fig. 4.)

position and'engaging liring pin 12.' Whenin the aforesaid position, the beveled walls are mating at an anglev end as at'25, and ashorter lever 26 pivoted as at 27 -to` Patented Aug. 9, 1960 j As shown in Fig. l, release member 20 is in its locked the other end of lever 24. Lever 26 is provided with a Y rounded lnose 28 Yon its free end which is adapted to be received in a rounded notch 29 provided in release member 20 and in the l'o'cked Vposition retains pin 12 andrrelease I 20 against a shoulder 30 formed by an insert 31Y in cham- "ber 18 and a` shoulder 32 formed by housing`10. Pin

12 and release 20 -therefore cannot separate unless lever 24 is rotated about pivot 25. Means for controlling lever 24 is provided 'andconsists of a bar 33 which is pivotally attached to lever 24 at its free end and extends into bore-3 5 for operativeconnection to a self-destruction time de- -V lay mechanism which consists of a gear train indicated generally vby 34 and which comprises gears 35, 36, V37,Vv

38,39 and 40 all being pivoted tov suitablesupporting structurerindioatedby 41.V Gear 40 is coaxially fixed` to a ratchet wheel 42 which is operably connected to a pawl 43. Gear wheel 35 carries 'a ooaxially ixed circular'cam 44 having alcircumferentially disposed notch 45 which-vl is adapted to receive 'an lintegral lug 46 on thelfo'rward end 'o f bar 33,. Lug 46normally rides against the. pe-n ripheral surface' of cam '44. Bar`33 is a notch 47 which is adapted to engagea lockingtab 4825"v fixed tol supporting 'structure 41. Awspring 49.k connected f atY one end Vto supporting'structure 41 :and barf33 urges-A' lug-46 againrstgthe 'peripheral surface'oflcam 44.Vv f vGear lwheel35 and cam 44 are^mounted for 'conjoint rotation on shaft '50 which .is'rot-ated by vice suchas-a clock springer the like(not shown),

suitable Means'rfor initiating the self-destruction mechanism"`rl force (not shown)fand settinga means for regulatingthe j may consist of a deviceop'erated by projectile set-back` `r= duration of thefdelay (also not, shown) may be provided.v

vTheoperation lof the mechanism is as 'followsz' Upon target impact, thel nose cap' 3 is crushed, thereby releasing the tension on the spring 17 which drives tiring" pin 12 rearwardlyY to tire the detonator 8; As the pin 12' l travelsrearwardly, lever 26 rotates" counterclockwise to'l I whereby ref-Y move* rounded nose 28 out of its notch 29 lease member 20 separates from pin 12.

Y In eventfthe projectile should miss the target-atwhichit is directed, and the nose cap is `not otherwise. disturbed; l

the projectile would become ,al fdud and therefore dan destruction mechanism will come into play and destroy the projectile after a predetermined period of time.

'The time delay mechanism is preset to operate at a given moment which has been calculated before tiring.

- In operation the gear wheel 35 together with cam 44 21 and the tiring pin 12 will fire the detonator 8 by lever 24 and free the `rounded nose 28 on lever 26 from notch 29 in release 20. The release 20 kwill then separate readily due to the beveled walls of notches 19 and action of spring 17.

The speed of gear wheel 35 will be controlled by the gear train 34 and the ratchet 42 and pawl 43.

It will be readily apparent that a highly reliable point detonating and self-destruction mechanism has been devsed.

The mechanism is entirely mechanical and will perform under most exacting conditions, especially with rockets travelling at speeds of 5,000 feet per second which present new problems such as instantaneous skin temperatures up to 2,000 F. `at thetip of thek nose and internal temperatures up to 600 F.

These excessive heats prohibit'the use' of protechnic,r

electronic or the like fuze mechanisms even when the fuze mechanisms are insulated from the outer skin of the fuze body. f f f It is to be understood that the form of the invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in f the shape, size and arrangements of parts may be resorted to,fwithout departing from the spirit of the invention, or

the scope of the subjoined claims. f f f f f What is claimed is:

f yl. In a fuze for attachment to a projectile including a body, a detonating charge in said ybody,'and a'hollow nose cap, a point detonatingmechanism for said fuze in said f body comprising a spring-loaded firing pin slidably mounted in said body and defining a forwardly extending stem portion, said stem being notched at its forward portion thereof, -a release member defining a rearwardly notched portion for detachable engagement `with said forwardly notched portion on saidfiring pin, a wire connecting said release member to said hollow nose cap for holding Said firing pin in a retracted position and Ato release said firing pin upon destruction of said nose cap, a self-destruction f mechanism adapted to release said firing pin upon failure of the destruction of said nose cap after a predetermined period of time comprising a first lever pivoted at one end in said body, a second lever having a shorter length than said first lever pivoted to the free end of said lever and defining a rounded nose at its free end, said nose adapted to be received in a rounded recess in said release member to retain said tiring pin and said release member in engaged relation, a time delay escapement mechanism mounted in said body forwardly of said release member, a circular cam having a circumferential notch adapted to be rotated by said escapement mechanism, a bar pivoted at one end to the free end of said first lever, a lug integral to the free end of said bar and extending under the circumferential surface of said cam and spring means urging said lug towards said circumferential surface of said cam whereby said notch on said cam engages said lug upon rotation of said cam to move said bar and said first lever and displace said second lever to move said nose on said second lever out of said recess in said release member to release said firing pin.

2. In a fuze for attachment to a projectile including a body having a series of coaxial bores therein, a frangible in a rearward said bore, a mechanism for the point detonation of said fuze comprising a housing in asaid bore forwardly of said detonator, said housing having an axial bore in its rearward portion and a chamber in its forward portion, said chamber being undercut at its forward portion to define a first shoulder in said chamber, a springloaded `firing member defining a head portion slidable in said bore in said housing, said head defining la firing point integral to its rearward face and an elongated stem portion integral to its forward face, said stem extending a substantial distance in said chamber` and provided with a notch in its forwardportion thereof, a release member defining a rearwardly'notched portion for detachable engagement with said notched forward portion on said stem portion of ksaid firing pin, an insert defining a second shoulder in said chamber, a wire connecting said release member and said nose 'cap to retain said firingpin in cocked position, said release member adapted to separate from and release said firing pin upon destruction of said nose cap, a first lever' pivoted Iatfone end yto said insert, a second lever of shorter length than said first lever pivotally connected to the free end of said first lever,-said second lever defining a nose aty its freer end for yengagement. in a recess in said release member and normally retain said release member and said firing pin stem in engaged position against said first yand second shoulders, a supporting structure arranged in a said bore in said body forwardly locking tab carried by said supporting structure for engagement'by said notch on said bar to rhold said bar against lateral movement and a spring urging said bar towards said cam whereby said lug will be engaged by said notch on said cam upon said counterclockwise rotation to free said bar from said lockingtab and move said bar forwardly to rotate said first lever and displace said nose on said second lever from said recess in said release member and free said firing pin.

3. In a device of the character claimed -in claim 2 wherein said notch in said firing pin defines a beveled forward wall and said notch in said release member defines a beveled rearward wall, said beveled walls adapted to mate at fan angle of 20 to a line perpendicular to the longitudinal axis of said firing pin when said firing pin and said release member are in said engaged relation.

References Cited in the file of this patent UNITED STATES PATENTS 1,330,424 Bergman Feb. 10, 1920 2,149,470 Schenk Mar. 7, 1939 2,306,941 Fontaine Dec. 29, 1942 2,369,626 Weiss Feb. 13, 1945 2,593,775 MacLean Apr. 22, 1952 2,889,778 Bennett June 9, 1959 

